Add SD logging and update docs

- Add optional microSD CSV logging per sender/day on receiver
- Wire logger into receiver packet handling
- Document new batch header fields, build envs, and SD logging
- Make sender links open in a new tab

src/main.cpp

@@ -13,6 +13,7 @@
 #include "web_server.h"
 #include "display_ui.h"
 #include "test_mode.h"
+#include "sd_logger.h"
 #include <stdarg.h>
 #include <math.h>
 #ifdef ARDUINO_ARCH_ESP32
@@ -625,6 +626,7 @@ void setup() {
     update_battery_cache();
   } else {
     power_receiver_init();
+    sd_logger_init();
     wifi_manager_init();
     init_sender_statuses();
     display_set_sender_statuses(g_sender_statuses, NUM_SENDERS);
@@ -806,6 +808,7 @@ static void receiver_loop() {
           data.link_valid = true;
           data.link_rssi_dbm = pkt.rssi_dbm;
           data.link_snr_db = pkt.snr_db;
+          sd_logger_log_sample(data, data.last_error != FaultType::None);
           for (uint8_t i = 0; i < NUM_SENDERS; ++i) {
             if (pkt.device_id_short == EXPECTED_SENDER_IDS[i]) {
               data.short_id = pkt.device_id_short;
@@ -897,6 +900,7 @@ static void receiver_loop() {
             data.err_decode = batch.err_d;
             data.err_lora_tx = batch.err_tx;
             data.last_error = static_cast<FaultType>(batch.err_last);
+            sd_logger_log_sample(data, (s + 1 == count) && data.last_error != FaultType::None);
           }
 
           if (sender_idx >= 0) {